This invention relates to the process for packing potato crisps into a container.
Generally, potato crisps are packaged into plastic tube bags in an upright position and sealed using a closure seam. Prior to sealing, the plastic tube bag is generally filled with a gas such as air or nitrogen gas to both protect the product from being crushed and maintain the freshness of the product by preventing oxidation during storage. The inflated, sealed tube plastic bag acts like a pillow or cushion, which is capable of receiving a certain level of applied pressure without the bag bursting and without the product therein being crushed. A typical bag of crisps is shown in FIG. 1A.
The problem associated with the packaging of potato crisps in this manner is that it is common for the product to be in the region of the closure portion of the bag. As such, it is difficult to apply to the closure seam by means of a thermal seal when such product lies across the closure portion of the bag.
A solution implemented to solve the problem associated with the above process includes the use of vibrations from air oscillations during the tube bag loading process. This results in a fast and convenient means to load the product into a tube bag, and ensures that residues from the product are removed from the closure seam region. Therefore, when the sealing means is applied to the product-loaded tube bag, the bag is successfully sealed and the absence of product residue at the sealing region ensures that the bag is correctly sealed.
However, when the potato crisps are dropped into the bag from a vertical position and/or the bag is vibrated, the product tends to congregate at the bottom of the bag, which results in a thicker and less uniformly spread volume of product within the bag. When the bag is inflated with nitrogen gas, the “cushion” formed therein will be less likely to protect the product from damage during packaging and storage as the volume of the product is not uniform throughout the area of the inflated bag. As such, during the usual test procedure for packaged potato crisps, whereby the inflated sealed bag is compressed between two flat surfaces to determine if the bag is inflated to industry standards, the uneven distribution of the potato crisps leads to the product being crushed during testing.
An issue also is the amount of space taken up by the protective atmosphere. It is estimated that a substantial portion of the volume packed for shipping is given over to accommodating the atmosphere rather than product. Snack foods have been developed which overcome this problem. Typically such snacks are reconstituted foods, which are made to a specific shape, for example crisps such as those sold as Pringles™, and are shaped for nesting together in a compact arrangement. While such products do allow for more efficient packaging (because the food items being regularly shaped fit together without any lost space) they are not suitable for non-reconstituted potato crisps which are different in size and shape to begin with (because they come from differently sized and shaped potatoes) and which become even more non-uniform in shape while being fried.
A purpose of the present invention is to address some of the above problems and provide a more efficient and desirable process for filling a container with such products.